[CMake] WIN32 definition gone in cmake 2.4.2

[Mike Talbot]

Hello,

I'm in the process of upgrading from cmake 2.2.3 to 2.4.2 and found that 
the new version doesn't define the preprocessor symbol WIN32 (which 
2.2.3 used to) for the VS 7.1 generator.  Is this a bug or feature?  (I 
can work around the problem by defining it explicitly with 
ADD_DEFINITIONS(-DWIN32) but I was wondering why it has changed, unless 
I'm doing something wrong).

Thanks,
Mike